Storm drain sediment filter

ABSTRACT

A storm drain sediment filter that can be adapted to cover a catch basin and be held in place by a perforated grate. In one embodiment, the filter includes a frame including four L-shaped rigid members, each of which is provided with at least two spaced apart retaining members. The four L-shaped rigid members are arranged such that a rectangular frame is formed having a total of four overlapping sections. The retaining members engage one of the overlapping portions of the frame but slidably receives the other. No retaining ends are formed at the distal end of the slidably engaged L-shaped members to serve as a sliding boundary. Instead, the dimensions of the filter bag are such that the filter bag serves to define the maximum dimension of the frame and thereby maintain the overlapping L-shaped rigid members in slidable engagement with each other. A circular embodiment is also disclosed.

BACKGROUND OF INVENTION Field of Invention

The present invention relates to.

This invention relates to a storm drain sediment filter configured tospan an opening of a catch basin.

Description of Related Art

Sasaki et al., U.S. Pat. No. 7,201,843, discloses a storm drain sedimentfilter that includes an adjustable frame from which a filter including acollar and a filter bag is suspended. In a rectangular embodiment, thelength and width dimensions of the frame of the storm drain sedimentfilter according to Sasaki et al. can be adjusted to accommodate catchbasins of various dimensions. In use, the length and width dimensions ofthe frame are adjusted such that the frame can be captured between aperforated storm grate and a recessed ledge of a catch basin on whichthe storm grate rests. Storm water passes through the filter material,and sediment flowing with the storm water is captured on the collarand/or in the filter bag.

Sasaki et al. teach that the frame comprises four L-shaped rigidmembers, each of which is provided with a retaining member. The fourL-shaped rigid members are arranged such that a rectangular frame isformed having a total of four overlapping sections. The overlappingportions of the frame are slidably engaged by means of the retainingmember, which is joined to one of the rigid members but slidablyreceives the other. To prevent the separation of the L-shaped rigidmembers when the dimensions of the filter are adjusted, Sasaki et al.teach that retaining ends are formed at the distal end of the slidablyengaged L-shaped members. The retaining ends serve as a sliding boundarythat cannot be withdrawn through the retaining members. Sasaki et al.teach that the retaining ends can be formed by flattening (i.e.,deforming) the distal ends of the slidably movable rigid members such asshown in FIGS. 6a and 6b of Sasaki et al. (see element 80 in suchfigures). It is also known that one can form retaining ends by bendingthe distal ends of the slidably engaged L-shaped members such that theycannot be withdrawn through the retaining members.

The storm drain sediment filter according to Sasaki et al. is superior,in many respects, to other storm drain sediment filter devices presentlyavailable in the market. But there is a need for improvement. Inparticular, the presence of retaining ends on the distal ends of theL-shaped members is prone to damage the filter suspended from the frameduring use. This is particularly problematic when the filter is formedof geotextile fabrics.

BRIEF SUMMARY OF THE INVENTION

In view of the foregoing, the present invention is directed toward animproved storm drain sediment filter that is configured to span anopening of a catch basin and which can be retained, at least in part, bya perforated grate for the catch basin. In one embodiment, a storm drainsediment filter according to the invention comprises a frame comprisedof four L-shaped rigid members, each of which is provided with at leasttwo spaced apart retaining members. The four L-shaped rigid members arearranged such that a rectangular frame is formed having a total of fouroverlapping sections. The overlapping portions of the frame are slidablyengaged using at least two spaced apart retaining members per side,which are joined to one of the rigid members but slidably receive theother. However, no retaining ends are formed at the distal end of theslidably engaged L-shaped members. Instead, the dimensions of the filterbag that receive the frame are limited such that the filter serves todefine the maximum dimension of frame expansion, which thereby maintainsthe overlapping L-shaped rigid members in slidable engagement with eachother (i.e., the filter prevents withdrawal of the slidably engagedL-shaped members from the retaining members). The omission of retainingends prevents the retaining ends from damaging the filter material,which is particularly useful when geotextile fabrics are used. Inanother embodiment of the invention, the frame is circular and includestwo spaced apart retaining members and a slidably received frame portionthat does not include a retaining end. Again, the dimensions of thefilter serve to define the maximum dimension of frame expansion.

The foregoing and other features of the invention are hereinafter morefully described and particularly pointed out in the claims, thefollowing description setting forth in detail certain illustrativeembodiments of the invention, these being indicative, however, of but afew of the various ways in which the principles of the present inventionmay be employed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a storm drain sediment filterconstructed and installed according to a preferred embodiment of theinvention shown in exploded view.

FIG. 2 is a side sectional view of the preferred embodiment of theinvention shown in FIG. 1 (non-exploded view).

FIG. 3 is a top plan view of the storm drain sediment filter shown inFIG. 1.

FIG. 4 is a top plan view in partial cutaway of the storm drain sedimentfilter shown in FIG. 3 in a partially collapsed or contracted condition.

FIG. 5 is a top plan view in partial cutaway of the storm drain sedimentfilter of FIG. 4 shown in a maximally dimensioned or extended condition.

FIGS. 6a and 6b illustrate the preferred configuration of the retainingmembers, which allow for adjustment of the dimensions of the storm drainsediment filter in extended and contracted positions, respectively.

FIG. 7 is a schematic sectional view of an exemplary retaining member asshown in FIGS. 6a and 6b as installed within the filter and resting onthe recess of the catch basin.

FIG. 8 is a top plan view in partial cutaway of a storm drain sedimentfilter constructed according to a second embodiment of the invention foruse with circular catch basin inlets.

FIG. 9 is a top plan view of a section of geotextile fabric as cut outand marked for use in forming a collar portion of a filter.

FIG. 10 is a top plan view of a section of geotextile fabric as cut outfor use in forming a first embodiment of a filter bag portion of afilter.

FIG. 11 is a top plan view of a section of geotextile fabric as cut outfor use in forming a second embodiment of a filter bag portion of afilter.

FIG. 12 is a top plan view of a section of geotextile fabric as cut outfor use in forming a third embodiment of a filter bag portion of afilter.

DETAILED DESCRIPTION OF THE INVENTION

A storm drain sediment filter constructed according to a preferredembodiment of the invention is shown generally at 10 in FIG. 1. Stormdrain sediment filter 10 is intended to be installed within abelow-grade 20 catch basin 30 of a type having basin sidewalls 40 andfloor 50 defining a chamber 60. A sewer pipe 70 extends away from one ofthe sidewalls 40 a distance above the floor 50. There would typically befour sidewalls for a rectangular chamber and one continuous sidewall fora cylindrical chamber. The catch basin 30 includes an upper end defininga catch basin inlet 80 and a recess 90 located at the upper end intowhich a grate 100 is normally received.

As shown also in FIGS. 2 and 3, storm drain sediment filter 10 includesa two-dimensional support frame 110 adapted to be received within andrest upon recess 90 of catch basin 30 and beneath grate 100. As thecatch basin inlet 80 has a rectangular opening into catch basin chamber60, frame 110 must be similarly rectangular and sized with a length andwidth for placement on a horizontal surface of recess 90.

The storm drain sediment filter 10 further includes a filter portion 120that comprises a collar portion 130 and, preferably, a filter bag 140that is stitched to an opening 150 in the collar portion 130. The filterportion 120 can be made of any fabric capable of filtering sediment fromstorm water. The fabric may be woven or non-woven. A non-wovengeotextile fabric is presently preferred. The filter portion 120 iscoupled to the support frame 110 via loops 160 sewn in the fabric of acollar 130 (see, e.g., FIG. 7).

Filter bag 140 has an open top 170, closed bottom 180 and bag sidewall190, and is adapted to be positioned at the catch basin inlet 80 andsuspended within catch basin chamber 60. In some embodiments, filter bag140 includes overflow apertures 200 located at a top portion of the bagsidewall 190 to allow excess (unfiltered) water to exit the filter bag140 and into the catch basin during periods of heavy flow. In otherembodiments, no overflow apertures 200 are included in the bag sidewall190. It will be appreciated that the number and style of overflowapertures can be varied.

The filter bag 140 is preferably formed of a single piece of geotextilenonwoven fabric, which has been cut such as shown in FIG. 10 or 11 andstitched to form a filter bag 140 having a single bag sidewall 190, aclosed bottom 180 and a round open top 170. The closed bottom 180 of thefilter bag 140 is formed via a bottom seam 210, and the continuoussingle bag sidewall 190 is formed via a side seam 220. A single piece ofthe same geotextile fabric used to form the filter bag 140 is also usedto form the collar portion 130. As shown in FIG. 9, a centrally locatedcircular cutout 230 is formed in collar portion 130, and the topmostportion of the filter bag 140 (i.e., the portion at the open top 170) isstitched to the collar portion 130 at the circular cutout 230 via seams240 so that the bag is inserted within the cutout 230 and drops belowthe level of the collar portion 130. Material along the periphery of thecollar portion 130 is folded back and affixed via seam 250 to the collarto form the loops 160 through which the 110 frame is received. Thefilter bag is preferably made of the same material as the collarportion, but could be made of a different fabric material, if desired.

Lifting straps 260 are preferably stitched into the collar portion 130at opposite sides. The lifting straps 260 allow a single person to liftthe storm drain sediment filter 10 from a catch basin 30 when the filterbag 140 is sufficiently full of sediment to justify replacement or thestorm drain sediment filter 10 has been in place for a predeterminedamount of time. Oil absorbing inserts (not shown) as are known in theart can be attached to the lifting straps 260, to filter portion 120and/or the frame 110, if desired. Most preferably, oil absorbing insertsare attached to tabs 440 (see FIGS. 10-12) provided on an inner side ofthe filter bag. Oil absorbing inserts absorb hydrocarbons that may flowinto the catch basin, thereby preventing the same from continuingthrough the storm drain system.

FIG. 4 is a top plan view in partial cutaway of the storm drain sedimentfilter 10 shown in FIG. 3 in a partially collapsed or contractedcondition. As noted above, the frame 110 is adjustable in two dimensionsso that both (or either) the width and the length of support frame 110can be adjusted to allow the frame 110 to be fitted within catch basinsof various dimensions. Frame 110 includes four L-shaped rigid members270 a-270 d, with members 270 b and 270 d being first and secondadjacent rigid members to member 270 a, respectively, and member 270 cbeing the opposed L-shaped rigid member to member 270 a. All four of theL-shaped rigid members 270 a-270 d can be identical, but typicallyL-shaped rigid members 270 a and 270 c are identical to each other, withL-shaped rigid members 270 b and 270 d being identical to each other butof a different length than L-shaped rigid members 270 a and 270 c.

A first retaining member 280 a is fastened at an end portion 290 a ofthe L-shaped rigid member 270 a, and at least a second retaining member300 a is fastened to the L-shaped rigid member 270 a in a spaced apartrelationship with respect to the first retaining member 280 a. Thespaced apart distance is preferably within a range of from about 0.5″ toabout 5″, with a spacing of about 2″ being presently preferred.Additional retaining members can be fastened to the L-shaped rigidmembers, if desired. But two retaining members per L-shaped rigid memberis presently believed to be sufficient. The opposite second end portion310 a of L-shaped rigid member 270 a is not provided with any retainingends. In other words, the dimensions of the L-shaped rigid member 270 ado not exceed the dimensions of the L-shaped rigid member 270 whenviewed in section at the second end 310 a as compared to section viewstaken through the L-shaped rigid member 270 a intermediate the first endportion 290 a and second end portion 310 a. This is also the case withL-shaped rigid members 270 b, 270 c and 270 d, which are labeled usingthe same reference numbering system as L-shaped rigid member 270 a.

Adjacent L-shaped rigid members overlap with each other in overlappingsections 320 (only one overlapping section 320 is illustrated). Forexample, in the overlapping section 320 shown in FIG. 4, the second endportion 310 a of L-shaped rigid member 270 a has passed through theretaining members 280 b and 300 b fastened to L-shaped retaining member270 b and extends beyond the first end portion 290 b of L-shaped rigidmember 270 b. The retaining members 280 b and 300 b are not fastened toL-shaped rigid member 270 a, but are slidably received thereby. Theremaining L-shaped rigid members 270 b, 270 c, 270 d are arranged withrespect to adjacent L-shaped rigid members so that there are a total offour overlapping sections such as section 320 are formed, therebyforming a rectangular support frame 110.

The configuration of the overlapping sections 320 permits adjustment ofthe width and/or length of the frame 110 by movement of the slidablyreceived portion of the L-shaped rigid member with respect to theadjacent L-shaped rigid member to which retaining members have beenfastened. An increase in the length and or width dimension of the frame110 can be accomplished by sliding the slidably received L-shaped memberwith respect to the adjacent L-shaped member as shown by the arrow 330in FIG. 6a . Similarly, a reduction in the length and or width dimensionof the frame 110 can be accomplished by sliding the slidably receivedL-shaped member with respect to the adjacent L-shaped member as shown bythe arrow 340 in FIGS. 6 b.

FIG. 4 shows the filter portion 120 in a somewhat contracted state andFIG. 5 shows the same filter portion 120 in a fully expanded state. Theloops 160 in the collar portion 130 limit the maximum degree to whichthe frame 110 can be expanded in both a length and width direction. Thismaximum degree is selected such that the second end portions 310 a, 310b, 310 c and 310 d are not capable of being withdrawn through retainingmembers 300 b, 300 c, 300 d and 300 a, respectively.

The retaining members 280 a-280 d and 300 a-300 d are preferably of thetype used in the bedding industry, and comprise a portion that isfastened to one L-shaped rigid member by a clamping force, but hassufficient spacing to allow the adjacent L-shaped rigid member to slidethrough. Preferred fasteners of this type have a nylon portion, whichcontacts the slidably received portion of the L-shaped rigid member. Thepresently most-preferred fastener is available from Sigma Clips as partnumber CLP4.

As noted above, no retaining ends are formed or provided at the secondends of the L-shaped rigid members. The elimination of retaining endshelps reduce tearing and other damage caused to the filter portion byprior art devices that include retaining ends.

A side view of a portion of the storm drain sediment filter 10 is shownin section in FIG. 7. In this section, the first end portion 290 b ofL-shaped rigid member 270 b is visible. First fastener 280 b has beenfastened to L-shaped rigid member 270 b by a clamping force. L-shapedrigid member 270 a is slidably received by fastener 280 b (and also by300 b, which is not visible in FIG. 7). The frame is received withinloop 160 sewn within the collar portion 130. Thus, the L-shaped rigidmembers can be manipulated to lengthen or shorten the frame so as to beable to rest on the horizontal surface of the recess 90 formed at thecatch basin inlet 80. As shown in FIG. 2, the collar portion 130, whenused in the catch basin, is dimensioned so that it does not extend pastthe recess to a point outside the grate 100.

An alternate embodiment useful to fit round catch basin inlets is shownat 10′ in FIG. 8. The support frame 110′ of filter 10 includes anannular rigid member 270′ having first a first end portion 290′ and asecond end portion 310′. A first retaining member 280′ is fastened tothe annular rigid member 270′ at the first end portion 290′, and asecond retaining member 300′ is fastened to the annular rigid member270′ in a spaced apart relationship with respect to the first retainingmember 280′. The spacing is preferably as disclosed above with respectto the first embodiment. No overflow apertures are shown in theillustrated embodiment. But they could be included, if desired.

The portion of the annular rigid member 270′ disposed inwardly of thesecond end portion 310′ is slidably received by the retaining members280′ and 300′, thus allowing the circumference of the annular ring to beadjusted to fit within the circular catch basin. The maximum dimensionof the frame 110′ is limited by the dimensions of the collar portion,and no retaining ends are provided on the second end portion 310′ of theannular rigid member 270′.

The method of manufacturing a storm drain sediment filter according tothe invention is described with reference to FIGS. 9-12. The collarportion 130 is formed by cutting a single piece of geotextile fabricgenerally as shown by cutout 350 in FIG. 9. The filter bag is formed bycutting a single piece of textile fabric generally as shown by cutouts360 and 370. The filter bag may, or may not, be provided with overflowapertures 200. FIG. 10 shows a cutout 360 for a filter bag that includesoverflow apertures 200. FIG. 11 shows a cutout 370 for a filter bag thatincludes overflow apertures in the form of vertical slits, which may bein the form of one or more long slits 450, one or more perforated longslits 450′ or one or more combinations of long and perforated slits450″. Initial testing of the use of apertures in the form of verticalslits surprisingly shows that they may be more effective at trappingsediment over a wider range of flows than other apertures known in theart (e.g., squares and scallops), while at the same time reducing therisk of backups. And FIG. 12 shows a cutout 370 for a filter bag thatdoes not include overflow apertures. The filter bag is formed by joiningsides 380, 390 to each other using stitch 220 (see FIG. 1), and sides400, 410 to each other using stitch 210 (see FIG. 2). The remainingperimeter edge 420 is stitched to an opening 150 in cutout 350 using astitch 240 (see FIG. 3). A frame 110 is laid onto the collar portion 130such that it is received between the spaced apart markings 430 shown inFIG. 10. The perimeter edge of the collar portion 130 is folded over theframe to create a loop 160, and stitched 250 as shown in FIG. 7.

To use a storm drain sediment filter according to the invention, a userfirst places the storm drain sediment filter over the grate of a catchbasin and extends the frame such that it defines a rectangle having thegenerally the same dimensions as the grate. The grate of the catch basinis then removed, and any dirt and debris on the receiving edge of thecatch basin inlet is removed. The storm drain sediment filter is thenplaced in the catch basin such that the perimeter edge containing theframe rests on the horizontal portion of the catch basin which normallysupports the grate. If an oil absorbing insert is to be used, it isattached at this point. The corners of the frame are extended to pressagainst the side of the receiving edge of the catch basin, and the grateis placed on the storm drain sediment filter.

During use, ground water and solids (i.e., sediment) flow through thegrate and onto the storm drain sediment filter. Water flows through thegeotextile material of the filter portion, which filters out andcaptures solids, predominantly in the filter bag. Once the storm drainsediment filter has accumulated a sufficient quantity of sediment or hasreached an end of life period, it can be replaced by a single person. Todo so, the person removes the catch basin grate, grabs the loop handlesremoves it from the grate for disposal. A new storm drain sedimentfilter is then placed into the catch basin.

It will be appreciated that the dimensions and materials used tofabricate storm drain sediment filters according to the invention canvary according to the particular situations. Generally speaking,L-shaped rigid members (or annular members) can be made from 8 gaugemetal wire. If a stronger frame is required, 6 gauge metal wire can beused. The clips used as retaining members must be dimensioned accordingto the gauge of the wire used. The geotextile material is preferably an8:0 ox/yd² non-woven geotextile material that has been approved for usein the fabrication of storm water drain filters by various regulatoryagencies. The lifting straps can be made form nylon webbing. The threadused in the stitching is preferably a polyester thread. However, itwould also be possible to join the geotextile fabric together usingsonic welding process.

Additional advantages and modifications will readily occur to thoseskilled in the art. Therefore, the invention in its broader aspects isnot limited to the specific details and illustrative examples shown anddescribed herein. Accordingly, various modifications may be made withoutdeparting from the spirit or scope of the general inventive concept asdefined by the appended claims and their equivalents.

What is claimed is:
 1. A storm drain sediment filter comprising: anadjustable frame comprising four L-shaped rigid members, wherein eachL-shaped rigid member has a first end and a second end, wherein a firstretaining member is non-slidably fastened to the first end of eachL-shaped rigid member and at least a second retaining member isnon-slidably fastened to each L-shaped rigid member in a spaced apartrelationship relative to the first retaining member such that thespacing between the first retaining member and the second retainingmember is between about 0.5″ and about 5″, and wherein the four L-shapedmembers are arranged to form a rectangular shape such that a portion ofeach L-shaped rigid member inward of the second end is slidably receivedby first and second retaining members non-slidably fastened to anadjacent L-shaped rigid member; and a filter portion comprising a collarportion that includes a seam that forms a loop that encapsulates theadjustable frame such that the filter portion spans the adjustableframe; wherein the filter portion further comprises a filter bag that issuspending from an opening provided in the collar portion; wherein nostructure is formed on or provided on the L-shaped rigid members whichwould prohibit the portion of each L-shaped rigid member inward of thesecond end that is slidably received by first and second retainingmembers non-slidably fastened to the adjacent L-shaped rigid member andthe second end from being withdrawn from the first and second retainingmembers non-slidably fastened to the adjacent L-shaped rigid member byexpanding the adjustable frame, and wherein the loop that encapsulatesthe adjustable frame limits a maximum expanded dimension of theadjustable frame such that no second end of any L-shaped rigid membercan be withdrawn from the first and second retaining membersnon-slidably fastened to the adjacent L-shaped rigid member.
 2. Thestorm drain sediment filter according to claim 1, wherein the filter bagis provided with overflow apertures.
 3. The storm drain sediment filteraccording to claim 2, wherein the overflow apertures are in the form ofvertical slits in a sidewall of the filter bag.
 4. The storm drainsediment filter according to claim 3, wherein at least a portion of thevertical slits are perforated vertical slits.
 5. The storm drainsediment filter according to claim 1, wherein the first and secondretaining members are spaced apart from each other a distance within therange of 1.0″ to 3.0″.
 6. The storm drain sediment filter according toclaim 1, wherein the first and second retaining members include a nylonportion that contacts the slidably received L-shaped rigid members. 7.The storm drain sediment filter according to claim 1, wherein theL-shaped rigid members are formed of steel wire having gauge within therange of from 6 gauge to 8 gauge.
 8. The storm drain sediment filteraccording to claim 1, wherein the filter portion is fabricated fromnon-woven geotextile material.
 9. The storm drain sediment filteraccording to claim 1, wherein the filter portion further compriseslifting straps.
 10. The storm drain sediment filter according to claim1, wherein the first retaining member is non-slidably fastened to thefirst end of each L-shaped rigid member by a clamping force.
 11. A stormdrain sediment filter comprising: an adjustable frame comprising anannular rigid member having a first end and a second end, wherein afirst retaining member is non-slidably fastened to the first end of theannular rigid member and at least a second retaining member isnon-slidably fastened to the annular rigid member in a spaced apartrelationship relative to the first retaining member such that thespacing between the first retaining member and the second retainingmember is between about 0.5″ and about 5″, and wherein a portion of theannular rigid member inward of the second end is slidably received byfirst and second retaining members non-slidably fastened to the annularrigid member; and a filter portion comprising a collar portion thatincludes a seam that forms a loop that encapsulates the adjustable framesuch that the filter portion spans the adjustable frame; wherein thefilter portion further comprises a filter bag that is suspending from anopening provided in the collar portion; wherein no structure is formedon or provided on the annular rigid member which would prohibit theportion inward of the second end that is slidably received by the firstand second retaining members non-slidably fastened to the annular rigidmember and the second end from being withdrawn from the first and secondretaining members non-slidably fastened to the annular rigid member byexpanding the adjustable frame, and wherein the loop that encapsulatesthe adjustable frame limits a maximum expanded dimension of theadjustable frame such that the second end of annular rigid member cannotbe withdrawn from the first and second retaining members non-slidablyfastened to the annular rigid member.
 12. The storm drain sedimentfilter according to claim 11, wherein the filter bag is provided withoverflow apertures.
 13. The storm drain sediment filter according toclaim 12, wherein the overflow apertures are in the form of verticalslits in a sidewall of the filter bag.
 14. The storm drain sedimentfilter according to claim 13, wherein at least a portion of the verticalslits are perforated vertical slits.
 15. The storm drain sediment filteraccording to claim 11, wherein the first and second retaining membersare spaced apart from each other a distance within the range of 1.0″ to3.0″.
 16. The storm drain sediment filter according to claim 11, whereinthe first and second retaining members include a nylon portion thatcontacts the slidably received portion of the annular rigid member. 17.The storm drain sediment filter according to claim 11, wherein theannular rigid member is formed of steel wire having gauge within therange of from 6 gauge to 8 gauge.
 18. The storm drain sediment filteraccording to claim 11, wherein the filter portion is fabricated fromnon-woven geotextile material.
 19. The storm drain sediment filteraccording to claim 11, wherein the filter portion further compriseslifting straps.
 20. The storm drain sediment filter according to claim11, wherein the first retaining member is non-slidably fastened to thefirst end of each L-shaped rigid member by a clamping force.